Many outdoor activities are greatly enhanced by the use of a portable seat or back support structure. While many such devices have been proposed in the prior art, all suffer from the limitations of bulk and/or weight. While many prior art structures may be folded or collapsed for transportation or storage, the rigid frames thereof retain their original dimensions. Consequently, the frame dimensions of such prior art chairs or seats, even in the folded or collapsed configuration are not reduced and the degree of compaction of such structures is thereby limited. In other words, when such prior art seats are folded or collapsed, they typically retain at least two dimensions (e.g., height and width), of their open, operational dimensions even in their collapsed state. When the activity for which a seat or backrest is required occurs a distance from a transportation source, the collapsed dimensions of prior art structures still present logistical problems due to their bulk when hand carrying them to the site of the activity.